Answer

$-1$

Work Step by Step

Recall the following rule: $a-(-b)=a+b$. Thus, we obtain:
$-11+10$
We can find the sum of a positive and a negative integer by subtracting the smaller absolute value from the larger absolute value and giving the result the sign of the original number that has the larger absolute value.
Since $|-11|>|10|$, we can subtract $10$ from $11$, giving us $1$. Since the larger absolute value was originally negative, we give our result the negative sign: $-1$